[R] How to transform the Matrix into the way I want it ???

[Nikhil Kaza]

  This is not an answer to your question, but I have used SparseM  
package to represent large travel time matrices efficiently.

?as.matrix.ssr

if the traveltime matrix is symmetric.

On 9 Nov 2009, at 5:24PM, Hongwei Dong wrote:

> Hi, R users,
>
> I'm trying to transform a matrix A into B (see below). Anyone knows  
> how to
> do it in R? Thanks.
>
> Matrix A (zone to zone travel time)
>
> zone z1 z2 z3  z1 0 2.9 4.3  z2 2.9 0 2.5  z3 4.3 2.5 0
>
> B:
>
> from to time z1 z1 0 z1 z2 2.9 z1 z3 4.3 z2 z1 2.9 z2 z2 0 z2 z3 2.5  
> z3 z1
> 4.3 z3 z2 2.5 z3 z3 0
>
> The real matrix I have is much larger, with more than 2000 zones.  
> But I
> think it should be the same thing if I can transform A into B.
>
> Thanks.
>
> Garry
>
> 	[[alternative HTML version deleted]]
>
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